Recombinant DNA Advisory Committee - 10/7-8/91 
pathogenicity" by the experts at the CDC. However, this list does not make 
recommendations. It includes agents of proven pathogenicity, of suspected pathogenicity, 
and of opportunistic organisms in immune compromised hosts. It is not clear where to 
draw the line. Possibly the RAC will have to create a working group which is charged 
not only with providing information, but also making recommendations to the RAC. 
Dr. McGarrity drew the committee's attention to a letter from Dr. Brinckerhoff. Dr. 
Schaechter summarized the letter for the group. In the letter, Dr. Brinckerhoff 
commented on the confusing nature of the submitted information as well as the lack of 
recommendations from the experts. She felt that the proposal is diffuse and 
unorganized. Those individuals, who are directly interested in reclassifying these 
organisms, should do so based on the information available. They should present the 
proposed reclassification to the committee for discussion and approval. Their proposal 
should have a concise and up-to-date listing of the organisms, the category into which 
they fall, and the appropriate references. 
Dr. B. Murray said it would have been much easier and more straightforward to have 
had a proposal that listed the specific organisms that are safe. Currently, it is too open 
because many of these organisms have suspected pathogenicity. 
Dr. McGarrity thanked Dr. Knudsen and Dr. McNeil for coming from the CDC to 
comment on the issue. 
Dr. Knudsen said he is the new Chief of Biosafety at the CDC in the Office of Health 
and Safety. The table was meant to provide information, not to make any 
recommendations. The difficulty arises as to how to define a pathogen, a suspected 
pathogen, and an opportunistic pathogen, and an appropriate place in the NIH 
Guidelines. The Actinomycetes are a good example of a group which contains these three 
kinds of pathogens. The regulations on how to handle these are somewhat obtuse. He 
introduced Dr. Mike McNeil, who is an expert on Actinomycetes. 
Dr. McNeil said he is a Medical Epidemiologist in the Mycotic Diseases Branch at the 
Division of Bacterial and Mycotic Diseases at the CDC. He stated that there are not a 
great number of animal studies which are needed to determine the pathogenicity of the 
organisms. The weakness in trying to classify these organisms is that there may be no 
reports for some of these organisms. Also, the taxonomy is shifting. In the table, the 
proven pathogens are the few organisms listed for which there are citations to animal 
studies. The suspected pathogens are designated if there is evidence in the literature of 
histologic invasion by the organism; or if in CDC review of clinical isolates, it has been 
observed that these organisms have been isolated from normally sterile sites. The list of 
opportunists includes those where there is a citation or where there is a patient 
mentioned as having acquired immunodeficiency syndrome, or another immune 
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